The most politically charged functional account of religion is the ideology critique associated with Karl Marx, who wrote in 1844 that religion is the sigh of the oppressed creature, the heart of a heartless world, and the opium of the people, a formula meaning both a genuine consolation and an anaesthetic that leaves the material conditions producing the pain in place, functioning in this reading to stabilize an unjust social order by redirecting attention from it. This account has drawn sustained scholarly criticism from several directions.
Historians and sociologists of religion have pointed to the substantial historical role of religiously motivated movements in challenging rather than stabilizing unjust social orders, including abolitionist Christianity, the American civil rights movement's roots in Black church leadership, and twentieth century liberation theology, each case read by critics as evidence that religion's social function is not reliably conservative in Marx's specific sense. Other critics, working from within the sociology and anthropology of religion, argue the ideology critique explains too little of religion's actual phenomenology, the felt, first person quality of religious experience, by treating belief primarily as a social byproduct rather than engaging what practitioners themselves report undergoing. This atlas records the ideology critique as one documented functional account among several, not as a settled explanation of religion as such, and states these criticisms in scholars' own terms rather than in this atlas's voice.